What are the three basic kinds of formed elements in blood, and what are their respective functions?
- Red Blood Cells - transporting oxygen into the body's tissues - White Blood Cells - the primary cells of the immune system, which has the important task of defending the body against viral, bacterial and parasitic attacks. - Platelets - Platelets are irregularly-shaped cell fragments that serve the primary function of hemostasis, which helps maintain the consistency of blood as well as keeping it inside of vessels, should they ever be punctured.
What function do keratinized and nonkeratinized stratified squamous epithelia have in common? What is the structural difference between these two? How is this structural difference related to a functional difference between them?
They both serve as a shield/protective layer. Keratinized tissue like the skin has lots of vessicles containing keratohyaline, a protein that eventually turns into keratine when the cell dies, providing that epithelium with protection and resistance to traction and friction, and it makes it impermeable.
Non keratinized tissue does not offer as much protection and allows the diffusion of materials through the cell junctions and the cell's body.
Name the three kinds of muscular tissue, describe how to distinguish them from each other in microscopic appearance, and state a location and function for each.
smooth- in artery and arteriole walls, internal organs, involuntary movement such as the gastrointestinal tract and esophagus. Smooth muscle is not striated.
skeletal- attached to bones, important for voluntary movement, limbs etc. Skeletal muscle is striated(dark and light lines)
cardiac- located only in heart. Cardiac muscle has intercalated discs (gap junctions) between cardiac cells so that the electrical flow can spread within the heart for contraction.
Contrast the merocrine and holocrine methods of secretion, and name a gland product produced by each method.
merocrine: have vesicles that release their secretion by exocytosis -ex: tear glands, pancreas, gastric glands
holocrine: cell accumulate a product and then the entire cell disintegrates- secretions is a mixture of cell fragments and the substance the cell had synthesized prior to its disintegration -ex: oil producing glands on eyelids and scalp
What do nervous and muscular tissue have in common? What is the primary function of each?
Nerve and muscle cells have a huge amount in common (nucleus, mitochondria and other organelles), however the property that they share that other cells do not have is the ability to react to electrochemical stimuli. Nervous tissue has two main functions: sensing stimuli and sending impulses to different parts of the body as a response. Muscular tissue main function is contraction
How do the epithelia of the esophagus and stomach differ? How does this relate to their respective functions?
esophagus - stratified squamous lines it to provide physical protection stomach - simple columnar lines it for protection secretion and absorption
Distinguish between regeneration and fibrosis. Which process restores normal cellular function? What good is the other process if it does not restore function?
Regeneration is the replacement of cells and fibrosis is where it involves repair by dent, forming scar tissues
Distinguish between a simple gland and a compound gland, and give an example of each. Distinguish between a tubular gland and an acinar gland, and give an example of each.
single: single unbranched duct. EX: Sweat Glands
compound: have a branched duct. EX: alivary glands, pancreas glands
tubular gland: the duct and secretary portion are of uniform diameter. EX:glands of the stomach
acinar gland: secretory cells form a dilated sac. EX: sebaceous glands
What features do most or all connective tissues have in common to set this class apart from nervous, muscular, and epithelial tissue?
The features that all connective tissues share in common is Fibroblasts.
Which of the following is not a function of simple columnar epithelium?
What embryonic germ layer gives rise to nervous tissue? To the liver? To muscle?
ectoderm gives rise to the epidermis and nervous tissue. The endoderm gives rise to the liver. The mesoderm gives rise to muscle.
Discuss the difference between dense regular and dense irregular connective tissue as an example of the relationship between form and function.
Dense Regular tissue is densely packed and has parallel collagen fibers and are tendons and ligaments. Dense irregular connective tissue is also densely packed but is randomly arranged. it also has collagen fibers but few visible cells. Dense irregular connective tissue can withstand unpredictable amounts of stress and is found in the deeper layers of skin and around organs.
Distinguish between differentiation and Metaplasia.
Metaplasia is the changing of one type of mature cell to another type of mature cell. Differentiation is unspecified tissues of embryo becoming specialized mature types.
Classify each of the following into one of the four primary tissue classes: the skin surface, fat, the spinal cord, most heart tissue, bone, tendons, blood, and the inner lining of the stomach.
Nervous- spinal cord,
Muscular- most heart tissue Connective- blood, tendons, bone
Epithelial- the skin surface, inner lining of digestive tract
What kinds of cells compose nervous tissue, and how can they be distinguished from each other?
Nervous tissue is composed of nerve cells called Neurons. They are distinguished by its own characteristic soma size, dendritic shape, source of synaptic input, destination of axonal output, and chemistry.